Search NASA⌕ Search

SEARCH · Search NASA

Results for “Earth entry”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

An Overview of Combined CFD and Material Response Simulations of Arcjet Experiments in Support of the Mars Sample Return Earth Entry System

This presentation will also include a top-level overview of the CFD/material response arcjet simulation process. A discussion will be made on the best-practices for running CFD solutions of arcjet experiments including how to determine the inflow conditions for the CFD solution from the arc heater settings. The required inputs to the material response solver will be presented, as well as a discussion of how they can be extracted from the CFD solution. Grid requirements for both the CFD and material response solver will be explored.

Thermal protection↗
NASA NTRS2010

Constellation Program Human-System Integration Requirements

The Human-Systems Integration Requirements (HSIR) in this document drive the design of space vehicles, their systems, and equipment with which humans interface in the Constellation Program (CxP). These requirements ensure that the design of Constellation (Cx) systems is centered on the needs, capabilities, and limitations of the human. The HSIR provides requirements to ensure proper integration of human-to-system interfaces. These requirements apply to all mission phases, including pre-launch, ascent, Earth orbit, trans-lunar flight, lunar orbit, lunar landing, lunar ascent, Earth return, Earth entry, Earth landing, post-landing, and recovery. The Constellation Program must meet NASA's Agency-level human rating requirements, which are intended to ensure crew survival without permanent disability. The HSIR provides a key mechanism for achieving human rating of Constellation systems.

Dory, Jonathan↗
NASA NTRS2018

Mars Sample Return: Grand Challenge for EDL

A year ago, I gave a talk in anticipation of a Mars Sample Return effort at the 9th Ablation Workshop. Since then a lot has happened. "April of this year, after a year of study phase, NASA and ESA (European Space Agency) signed a Statement of Intent (SOI) to jointly develop a Mars Sample Return plan to be submitted to their respective authorities by the end of 2019. This signing is historic, as it signals the desire, the readiness, and the willingness to work together to execute this inspiring mission, we all have the opportunity to tackle this grand challenge. We have the scientific and engineering maturity to identify the critical technologies ready to be applied, and with discipline this campaign can be executed affordably," Jim Watzin, Mars Program Executive, NASA. NASA Centers with JPL (Jet Propulsion Laboratory) leading the charge is in the midst of a pre-formulation phase for executing a Mars Sample Return before the end of next decade. The proposed talk builds on the previous year talk. In light of the agreement between NASA and ESA, NASA has assumed the responsibilities for developing the earth entry vehicle (EEV) that will fly along with a European Spacecraft and return with the sample from Mars. EEV will be deployed for entry into earth. The EEV design, development, testing and certification have to result in a highly reliable sample return system. The entire architecture has to be demonstrated to meet the planetary protection requirement. NASA is considering two distinctly different earth entry vehicle architectures and with each choice, many different ablative TPS (Thermal Protective Shield) candidates. As a result of the NASA-ESA ongoing studies, some of the key entry conditions and design requirements are better understood today and more are being scoped out. The heat-shield ablative TPS choice need to be done with a good understanding as it plays a very significant role in determining the robustness of the EEV. Knowledge about how materials and system perform, and how the features could become flaws and how flaws lead to failure, etc. need to be clearly understood and the knowledge then need to be used to down select the TPS. This proposed talk will provide greater insight into the progress being made and the challenges that need to be tackled.

Mars Sample Return: Grand Challenge for EDL↗
NASA NTRSDate not supplied

NASA Capture, Containment, and Return System: Bringing Mars Samples to Earth

The Capture, Containment, and Return System (CCRS) project is NASA’s last step in bringing back Mars samples. CCRS will close a decades-long multi-mission and multi-agency effort to bring Mars surface samples back to Earth for scientific studies. CCRS will launch in 2027 on the European Earth Return Orbiter (ERO) spacecraft, which will provide communications relay for the Mars Sample Return ground missions, Perseverance rover and the Sample Retrieval Lander (SRL) (to be launched in 2028). The main mission for CCRS begins when the first-ever orbital planetary capture operation occurs with CCRS catching and securing the Orbiting Sample (OS)in low Mars orbit. From this point, the system will perform additional "firsts": it will autonomously contain the OS with heat-shrink-fit, sterilize the outside surface, and assemble the Earth entry capsule, named Earth Entry System (EES), in orbit around Mars using a gantry mechanism. At approximately 2.8 Lunar distances from Earth, or 3-days from entry into Earth’s atmosphere, CCRS will open its micrometeoroid shield and release the EES on a ballistic trajectory to Earth. The EES is designed to be a fully passive system that will enter the atmosphere and land without parachute at the Utah Test and Training Range (UTTR).

Mars mission, Sample return, Mission design↗
NASA NTRS2016

Validation of High Speed Earth Atmospheric Entry Radiative Heating from 9.5 to 15.5 km/s

This paper presents an overview of the analysis and measurements of equilibrium radiation obtained in the NASA Ames Research Center's Electric Arc Shock Tube (EAST) facility as a part of recent testing aimed at reaching shock velocities up to 15.5 km/s. The goal of these experiments was to measure the level of radiation encountered during high speed Earth entry conditions, such as would be relevant for an asteroid, inter-planetary or lunar return mission. These experiments provide the first spectrally and spatially resolved data for high speed Earth entry and cover conditions ranging from 9.5 to 15.5 km/s at 13.3 and 26.6 Pa (0.1 and 0.2 Torr). The present analysis endeavors to provide a validation of shock tube radiation measurements and simulations at high speed conditions. A comprehensive comparison between the spectrally resolved absolute equilibrium radiance measured in EAST and the predictive tools, NEQAIR and HARA, is presented. In order to provide a more accurate representation of the agreement between the experimental and simulation results, the integrated value of radiance has been compared across four spectral regions (VUV, UV/Vis, Vis/NIR and IR) as a function of velocity. Results have generally shown excellent agreement between the two codes and EAST data for the Vis through IR spectral regions, however, discrepancies have been identified in the VUV and parts of the UV spectral regions. As a result of the analysis presented in this paper, an updated parametric uncertainty for high speed radiation in air has been evaluated to be [9.0%, -6.3%]. Furthermore, due to the nature of the radiating environment at these high shock speeds, initial calculations aimed at modeling phenomena that become more significant with increasing shock speed have been performed. These phenomena include analyzing the radiating species emitting ahead of the shock and the increased significance of radiative cooling mechanisms.

Equilibrium↗